Question

A physics student is standing on an initially
motionless,frictionless turntable with rotational inertia
0.31kg·m2. He's holding a wheel of rotational
inertia0.22 kg·m2 spining at 122 rpm about a
verticalaxis, as we showed in Fig. 11.8. When he turns the wheel
upsidedown, student and turntable begin rotating at 77 rpm.

Figure 11.8

(a) What is the student's mass, considering him to be
acylinder 30 cm in diameter?
??? kg

(b) How much work did he do in turning the wheel upside
down?Neglect the distance between the axes of the turntable
andwheel.
??? J